1. Field of the Invention
The present invention relates to a method for manufacturing a semiconductor device which involves a process control technique used in a process for particularly manufacturing a semiconductor device.
2. Background Art
Conventional process control techniques are often used based on sensor-derived data such as gas pressure and RF power of the inside of an apparatus. Besides, process controls are often performed in lots. That is, processes are conducted in such a way that one recipe corresponds to one lot. Take a gate etching process for instance. The etching is performed by changing the contents of a recipe into an optimum setting parameter value based on the sensor values of an etching apparatus. When there is a deviation in a gas pressure, the etching is performed after adjusting the value of the gas pressure. As a result, it is possible to perform the etching taking account of a change in the state of the reaction chamber of the etching apparatus (for example, JP-A No. 2002-9059).
Besides, since methods of manufacturing a semiconductor device are practiced by combining numerous process steps, all the steps including the management of lots are generally subjected to centralized management by a manufacturing execution system (MES). In such manufacturing methods, when a lot is fed to an apparatus, the apparatus inquires a process recipe of the MES. Then the MES transmits a recipe number corresponding to the lot to the apparatus. At this point of time, to change the recipe in response to the state of the reaction chamber as described above, a method is generally practiced in which the MES inquires of its associated system a process control method before the transmission of the recipe from the MES to the apparatus to transmit the result of the inquiry to the apparatus.
In conventional process control techniques, since the manufacturing execution system (MES) inquires of its associated system the process control method, a problem has arisen in that it is difficult to use a manufacturing method in which the process control is performed from one wafer to another. Also, another problem has arisen in that such a conventional system cannot handle process control which covers consecutive process steps, that is, process control which is performed based on a result effected at the next previous process step.